20906436205 has 16 divisors (see below), whose sum is σ = 26682614784. Its totient is φ = 15670713600.

The previous prime is 20906436181. The next prime is 20906436209. The reversal of 20906436205 is 50263460902.

It is not a de Polignac number, because 20906436205 - 2²⁷ = 20772218477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20906436209) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 532521 + ... + 570430.

It is an arithmetic number, because the mean of its divisors is an integer number (1667663424).

Almost surely, 2^20906436205 is an apocalyptic number.

It is an amenable number.

20906436205 is a deficient number, since it is larger than the sum of its proper divisors (5776178579).

20906436205 is a wasteful number, since it uses less digits than its factorization.

20906436205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103196.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 20906436205 in words is "twenty billion, nine hundred six million, four hundred thirty-six thousand, two hundred five".